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Biomedical subjects

R Ritch

Publications and source records attributed to R Ritch.

At least 235 records · Page 13Linked to original sources
PubMed1982

Nonprogressive low-tension glaucoma with pigmentary dispersion.

Four patients with nonprogressive glaucomatous cupping and nonprogressive visual field damage, three of whom were referred with a diagnosis of low-tension glaucoma, were found to have slit-like radial peripheral iris transillumination defects. Three of these patients had Krukenberg spindles and dense pigmentation of the trabecular meshwork. These findings are considered pathognomonic for pigmentary glaucoma. Little is known of the natural course of this disease. A decrease in corneal and trabecular pigmentation with age and normalization of intraocular pressures after years of treatment have been noted. The patients described here were all much older than the average patient with pigmentary glaucoma, yet in none of them had a diagnosis of glaucoma been made at the time the damage presumably developed. In these patients the pigmentary glaucoma had probably remitted spontaneously.

Age Factors↗
PubMed1982

Argon laser treatment for medically unresponsive attacks of angle-closure glaucoma.

Seven patients with medically unresponsive attacks of angle-closure glaucoma were successfully treated with the argon laser. Three methods may be used either singly or in combination to cut short an attack: (1) peripheral iridoplasty, (2) pupilloplasty, and (3) laser iridectomy. Laser treatment is preferable to and safer than intraocular iridectomy in such cases. Pilocarpine, which increases the axial length of the lens and shallows the anterior chamber, may worsen angle closure by increasing the pupillary block. An enlarged lens or forward movement of the lens may be a significant factor in medically unresponsive attacks. The routine use of copious amounts of pilocarpine should be avoided in treating angle-closure glaucoma.

Aged↗
PubMed1982

A positioning aid for eyedrop administration.

A device designed to improve the ability with which the patient instills eyedrops is described. This consists of a flexible, angled, vacuum-metallized polyester mirror with adhesive at one end to which a squeeze-type dropper bottle may be attached and, if desired, permanently affixed.

Equipment Design↗
PubMed1982

Ultrastructure of the eye in fetal type II glycogenosis (Pompe's disease).

Type II glycogenosis is an autosomal recessive storage disease characterized by absence of the enzyme acid alpha-1,4-glucosidase. The eye of a 16 week fetus, aborted after diagnosis by amniocentesis, was studied by light and electron microscopy. Extensive deposits of lysosomal and cytoplasmic glycogen were present in virtually all ocular tissues examined, with the notable exception of pigment epithelia (iris and retina). The massive glycogen deposits present in this, the youngest case thus far examined histologically, emphasize the involvement of the fetus from its earliest stages and the importance of prenatal diagnosis.

Eye↗
PubMed1981

Proton-beam irradiated epithelioid cell melanoma of the ciliary body.

A malignant ciliary body melanoma received proton-beam irradiation. After an apparent failure of the tumor to respond, the eye was enucleated. A predominantly epithelioid cell tumor appeared viable by light microscopy, and a low degree of mitotic activity persisted, despite therapy. The tumor cells, however, displayed degenerative changes ultrastructurally, presumably results of the radiotherapy. These consisted of numerous cytoskeletal filaments, lipid vacuoles, prominent phagolysosomes, and nuclear convolutions and fragmentations. The mitochondria were fewer in number in the present tumor than typically encountered in epithelioid cells. A rare leptomeric structure was discovered, probably an organizational modification of the cytoplasmic filaments. The tumor's capillaries showed radiation-induced changes in terms of thickened basement membranes and perivascular fibrin deposition. The foregoing features are indicative of cellular and metabolic injury from the radiotherapy, but these were evidently not sufficiently injurious to sterilize the tumor.

Adult↗
PubMed1981

Pathophysiology of glaucoma in uveitis.

Glaucoma secondary to uveitis may occur by any one or by a combination of several different pathophysiological mechanisms. These include acute angle-closure due to iris bombé caused by posterior synechiae; chronic angle-closure due to peripheral anterior synechiae; and open angle glaucoma due to obstruction and/or inflammation of the trabecular meshwork. Secretory hypotony may mask impairment of outflow, while steroids used to treat the uveitis may further complicate the situation by causing a rise in intraocular pressure. Careful delineation of the pathophysiology involved is the cornerstone of successful management.

Adrenal Cortex Hormones↗
PubMed1981

A modified Flieringa-Legrand ring for use in trabeculectomy.

The Flieringa-Legrand ring has been modified for use in trabeculectomy. It may be used with the Forbes scleral support system, which is designed to prevent posterior infolding of the sclera. This combination is particularly suited for filtration surgery on infantile and juvenile glaucoma and in high myopia, where vitreous loss is a potential threat.

Child↗
PubMed1980

Filtering valve implant surgery for eyes wtih neovascular glaucoma.

We performed filtration surgery with a unidirectional, pressure-sensitive valve implant in 40 eyes with neovascular glaucoma. The device consisted of an open Supramid tube (outside diameter 0.58 mm, inside diameter 0.38 mm) sealed to a Silastic tube with a slit valve. The Supramid tube was inserted at the corneoscleral limbus 1 to 4 mm into the anterior chamber and the Silastic portion was located under a lamellar scleral flap. Twenty-seven of 40 eyes (68%) had a postoperative IOP less than or equal to 24 mm Hg with a mean follow-up of 13.8 months. Ten of these 27 eyes required postoperative medical therapy to achieve this level of IOP control. The glaucoma valve implant failed to return IOP to normal in 13 of the 40 eyes (32%), 11 of these as a consequence of scarring of the external bleb.

Adult↗
PubMed1980

Electron microscopic observations of intravitreal Cysticercus cellulosae (Taenia solium).

Cysticercus cellulosae, the larval stage of Taenia solium, was studied by light and electron microscopy after its removal from the vitreous. The ultrastructure of the larva is highly organized and displays a superficial tegument and deeper parenchyma. The tegument contains a microvillous surface overlying a syncytial cytoplasm. A deeper muscular layer overlies the parenchyma, within which are highly specialized structures important in water balance, flame cells, and acid-neutralizing calcareous corpuscles.

Adolescent↗
PubMed1979

Clinical comparison of dipivalyl epinephrine and epinephrine in the treatment of glaucoma.

Dipivalyl epinephrine, 0.1%, though slightly less effective in decreasing intraocular pressure, showed significantly fewer side effects than epinephrine hydrochloride, 2%. Seventeen patients with symmetrically increased intraocular pressures who completed a six-month double-masked crossover study showed a significant decrease in intraocular pressure averaging 23.7% for dipivalyl epinephrine over the entire study and 27.4% for epinephrine. In the first treatment period, dipivalyl epinephrine was slightly less effective than epinephrine. In the second treatment period, dipivalyl epinephrine was statistically less effective than epinephrine. Two of the original 25 patients were dropped from the study because of epinephrine allergy or intolerance, one had uncontrolled pressures with either drug, and five failed to maintain adequate follow-up. Complaints of side effects such as burning and irritation occurred much more frequently in eyes receiving epinephrine (24%) than dipivalyl epinephrine (3%). Mild mydriasis occurred with each drug, averaging +0.65 mm with dipivalyl epinephrine and +0.55 mm Hg with epinephrine. No effect on blood pressure or pulse rate was found for the two drugs.

Adult↗